title: Evaluation of the PET component of simultaneous [(18)F]choline PET/MRI in prostate cancer: comparison with [(18)F]choline PET/CT.
abstract: OBJECTIVE
  The aim of this study was to evaluate the positron emission tomography (PET) component of [(18)F]choline PET/MRI and compare it with the PET component of [(18)F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer.
  
  
  METHODS
  Thirty-six patients were examined with simultaneous [(18)F]choline PET/MRI following combined [(18)F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUVmax and SUVmean) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUVmax and SUVmean was tested using Pearson's product-moment correlation and Bland-Altman analysis.
  
  
  RESULTS
  All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUVmax and SUVmean of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p<0.05 and 2.0 vs 2.6, p<0.001, respectively). Pearson's product-moment correlation indicated highly significant correlations between SUVmax of PET/CT and PET/MRI (R=0.86, p<0.001) as well as between SUVmean of PET/CT and PET/MRI (R=0.81, p<0.001). Bland-Altman analysis revealed lower and upper limits of agreement of -2.77 to 3.64 between SUVmax of PET/CT vs PET/MRI and -1.12 to +2.23 between SUVmean of PET/CT vs PET/MRI.
  
  
  CONCLUSIONS
  PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUVmax and SUVmean was found. Both SUVmax and SUVmean were significantly lower in [(18)F]choline PET/MRI than in [(18)F]choline PET/CT. Differences of SUVmax and SUVmean might be caused by different techniques of attenuation correction. Furthermore, differences in biodistribution and biokinetics of [(18)F]choline between the subsequent examinations and in the respective organ systems have to be taken into account.
authors.affiliation: Department of diagnostic and interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany, axel.wetter@uk-essen.de.
authors.forename: Axel
authors.initials: A
authors.lastname: Wetter
authors.forename: Christine
authors.initials: C
authors.lastname: Lipponer
authors.forename: Felix
authors.initials: F
authors.lastname: Nensa
authors.forename: Philipp
authors.initials: P
authors.lastname: Heusch
authors.forename: Herbert
authors.initials: H
authors.lastname: Rübben
authors.forename: Jens-Christian
authors.initials: JC
authors.lastname: Altenbernd
authors.forename: Thomas
authors.initials: T
authors.lastname: Schlosser
authors.forename: Andreas
authors.initials: A
authors.lastname: Bockisch
authors.forename: Thorsten
authors.initials: T
authors.lastname: Pöppel
authors.forename: Thomas
authors.initials: T
authors.lastname: Lauenstein
authors.forename: James
authors.initials: J
authors.lastname: Nagarajah
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000556:secondary; D002794:Choline / Q000031:analogs & derivatives*; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D012008:Recurrence; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: C516370:fluoromethylcholine; D002794:Choline